Introduction
For years there's been talk about Digital Television (DTV), though it's only been in the last year that manufactures have delivered products to their dealers and networks have started minimal broadcasting of HDTV content. Leading the way, CBS has aired three football games, an episode of Chicago Hope and just recently an episode of 48 Hours. The Los Angeles affiliate, KCBS, provides reruns of existing HDTV programming and high-quality sights of the city on a separate digital channel. On April 26th, NBC made TV history when "The Tonight Show with Jay Leno" became the first show to broadcast nightly in HD.

DTV encompasses both the High Definition (HDTV) and standard definition (SDTV) formats. HDTV formats are displayed in the 16:9 aspect ratio with a potential vertical resolution of 1080p (progressive), though 1080i (interlaced) is the maximum scan rate for current TV sets. The HDTV signal is delivered at 19.3 Mbps (bits per second) in a 6MHz channel. Delivered at the lower 480p resolution, SDTV is displayed in either 16:9 or 4:3 aspect ratios. Broadcasters have an affection for this later format because it allows them to multicast, the practice of sending multiple SDTV signals on a single 6MHz channel. Home-based DTV receivers are designed to accept all 18 formats, allowing consumers to receive what ever signal the network is sending. Canada, S. Korea, Taiwan and Argentina have also adopted this DTV standard.

The DTV Transition
Getting from an analog-based infrastructure to a totally digital one
requires cooperation from the broadcast, cable and consumer electronics
industries. While previous digital technologies were confined to
consumer acceptance via a proliferation of new products and software,
the DTV transition affects every level of the broadcast chain.

Currently, the only way to receive a HDTV signal is over-the-air with
the use of an antenna, though it's estimated that two-thirds of
Americans use cable to receive TV. With popular cable channels like HBO
and Discovery planning to produce and deliver HDTV programming, several
cable companies have started test trials and are making plans for
conversion. Some digital satellite systems have already committed to
providing both HDTV and SDTV.

To date, 17 cable operators in the U.S. and Canada have committed to
deploy Scientific-Atlanta's digital set-top box because it enables
owners of first- generation HDTV sets to secure high-definition
programming via cable. By the end of the year, some next generation
HDTV's and set-top boxes will incorporate the IEEE 1394 'FireWire'
standard for direct compatibility with cable.

Over-the-air broadcasts are currently available in 22 major markets but
all commercial stations must begin broadcasting no later than May 2002.
CEMA (Consumer Electronics Manufacturers Association) expects 150,000
DTV sets to be purchased by the end of 1999, primarily representing
early adopters and technology enthusiasts. In 2000, manufacturers
anticipate selling 600,000 sets. Realistically, it's going to require a
lot more consumer education, and every cable company coming to the
table for such expectations to be realized. The year 2006 is when the
DTV transition is scheduled to be in place and CEMA estimates the sale
of 10.8 million units, representing a penetration of 30%.

Like DVD, Dolby Digital 5.1 audio is the standard for HDTV, however,
broadcasters who've traditionally treated audio as the bastard
stepchild, find themselves unprepared for discrete 5.1 audio
transmissions. The production and distribution infrastructure of the
broadcast community is presently ensconced in the mono and stereo world
with millions of dollars tied up in equipment that is insufficient for
producing and delivering multi-channel broadcasts. In an effort to
facilitate multi-channel audio with existing equipment, Dolby Labs
developed Dolby E. This encode/decode process enables broadcasters to
distribute up to eight channels of audio via AES/EBU pairs, two audio
tracks from a digital video tape, a digital audio tape or video server.
Dolby E carries the Dolby Digital metadata for final delivery to a home
theater's Dolby Digital decoder.

Who's Doing What in DTV
Perhaps, the most ambitious supporter of HDTV is Unity Motion, a
company out of Utah, that operates a HDTV broadcast service with a
total of 3 HD channels. For consumers they market a High Definition
Distribution System, consisting of a widescreen monitor and HDTV
Receiver. They deliver a broad range of movies and sports 24 hours a
day, 7 days a week. It's important to note that they re-run a great
deal of material due to the shortage of HD content. Many audio/video
retailers use Unity Motion's signal for in-store demonstrations and
they were responsible for providing HDTV broadcasts to exhibitors
booths throughout this year's CES. The addition of more channels is
scheduled for 1999 and 2000. The company has secured significant
capital for the acquisition of first-run programming and operates its
own production facilities for the creation of original programming in
HD.

Toshiba is shipping three large screen (71 inch to 65 inch) HDTV-ready
color TVs equipped with both DTV (1080i) and DVD (480p) inputs. All
units feature a DTV interface terminal (33.75 KH scanning rate),
enabling the maximum picture resolution for all 18 DTV broadcast
formats. These units interface with both a DTV set-top box and a
Progressive Scan DVD video player simultaneously. Pioneer's first HDTV
is the 64" Pro-700HD. The exclusive Automatic Format Converter
upconverts conventional NTSC signals to 480p, and all DTV signals are
displayed at 1080i. Sony is shipping the 65-inch projection HDTV,
KWP-65HD1, and the 34" direct view KW-34HD1. Both feature Digital
Reality Creation (DRC), which doubles scan line pixels to create an
image with four times the density of other TVs.

As with any new consumer technology, early DTV products are going to be
pricey. Sets incorporating high-definition receivers will exceed
$7,000. HDTV ready units will start as low as $2799, but will require a
separate set-top converter to actually receive the digital signal. Once
there is a variety of programming, demand will increase and equipment
prices should start falling.

Conclusion
With all the major networks ramping up for the new age of digital TV
and retailers slowly adding DTV-ready products to the shelf, it would
appear that DTV is no longer vaporware but a real technology with a
future. Still, it's not quite ready for primetime with sporadic
broadcasts, limited access and costly home-based equipment.

It's safe to say that analog broadcasts will continue for at least
eight years, possibly longer. With set-top boxes that receive and
downconvert digital signals, older analog sets can be used long after
the termination of analog signals. Of course, you won't be enjoying the
sharp and brilliant images of HDTV but you will be able to watch TV as
you do now. Federal legislation will insure continuation of analog
signals in markets where DTV penetration is less than 85% percent. Like
any purchase, buy as much of the most current technology as you can
afford to ensure the longest life. Rest assured that all DTVs are
backward compatible with today's VCR and DVD players.

For complete monthly updates on the advancement of DTV bookmark this
comprehensive website www.digitaltelevision.com. It contains articles
from industry experts like Joe Kane and key developers in the field
plus an up-to-date list of station(s) broadcasting HDTV programming.